package sample.RTTI;

class Useful {
	public void f() {
	}

	public void g() {
	}
}

class MoreUseful extends Useful{
	public void f() {
	}

	public void g() {
	}
	
	///child private method
	public void u(){
		
	}
}

public class rttis {
	public static void main(String[] args){
		Useful[] x={
				new Useful(),
				new MoreUseful()
		};
		
		x[0].f();
		x[1].f();
		
		((MoreUseful)x[0]).u();//Exception Here
		((MoreUseful)x[1]).u();
	}

}
